Follicle-stimulating hormone (FSH) is released by the pituitary gland and regulates the functioning of the gonads and the production and maturation of gametes. FSH is generally released by the pituitary gland upon prior release of a triggering hormone, such as gonadotropin-releasing hormone.
FSH release is necessary for ovulation in females and for maturation of sperm in males. In females, FSH stimulates follicular granulosa cell proliferation in the ovary and impacts synthesis of estrogen, a hormone which is integral to follicular maturation and ovulation. In males, FSH is involved in the maturation of sperm cells. More specifically, FSH action in males is directed at the Sertoli cells, which are a recognized target of the hormone and which support the process of sperm maturation (spermatogenesis). FSH is also produced in the prostate, where it is an important mediator of cell growth.
Accordingly, inhibitors of FSH release are useful as contraceptive agents in both males and females.
In addition to the function in fertility, FSH also plays a role in several disease states. Increased levels of FSH receptor are associated with prostate cancer, with the highest levels associated with hormone-refractory prostate cancer. Prostate cancer is the most common cancer in American men, with more than 230,000 new cases diagnosed each year. Approximately 30,000 deaths will be attributed to prostate cancer in 2004 (Jemal A, Tiwari R C, Murray T. Ghafoor A, Samuels A, Ward E, Feuer E J, Thun M J. Cancer statistics 2004. CA Cancer J. Clin. 54:8-29, 2004). Approximately 40% of individuals treated with surgery or radiation will develop recurrent prostate cancer (Walsh P C, Retik A B, Vaughan E D, eds. Campbell's Urology. 7th ed. Philadelphia, Pa.: WB Saunders Company; 1998). The most common treatment for recurrent prostate cancer is the suppression of testicular testosterone production via orchiectomy, estrogen treatment, antiandrogen administration, and/or GnRH agonist/antagonist treatment. This usually results in remission for 2-3 years, after which time prostate cancer becomes “hormone refractory,” meaning that it develops the ability to grow despite the reduction of blood androgen concentrations to castrate levels. Consequently, improved compositions and methods are needed for treating prostate cancer, in particular hormone refractory prostate cancer.
Pituitary tumors (adenoma) are non-cancerous growths that typically affect different hormone-producing regions, depending on the specific location of the tumor. Pituitary tumors account for about 15% of intracranial tumors, and are associated with significant morbidity due to local compressive effects, hormonal hypersecretion, or treatment-associated endocrine deficiency (Heaney A. P., et al.: Molecular Pathogenesis of Pituitary Tumors. In: Oxford Textbook of Endocrinology, Wass J. A. H. and Shalet S. M., (Eds.), Oxford University Press, Oxford, 2002 (in press)). The great majority of pituitary adenomas are benign and are relatively slow growing. Pituitary tumors may, however, lead to overproduction of one or more of the pituitary hormones. FSH-secreting pituitary tumors often lead to the development of multicystic ovaries and to elevated estradiol levels. In turn, increases in estradiol levels contribute to health risks including endometrial and prostate cancer. Consequently, improved compositions and methods are needed for treating symptoms associated with FSH-secreting pituitary tumors.
Accordingly, compounds that inhibit FSH secretion are useful in a variety of treatments.
It is an object of the present disclosure to provide compositions and methods that may be used to decrease FSH levels, and such compositions and methods may be used, for example, in contraception and for the treatment of a variety of FSH-related disorders.